← Back to Patent Explorer
US4818463A Expired / Lapsed US ⏱️ 0.0 years remaining

Process for preparing non-woven webs

Assignee: Reifenhauser KG
•
Filing: 1987-11-20
•
Granted: 1989-04-04
•
Expires: 2007-11-20
📄 Original PDF 🌐 Google Patents 🔄 Sync Now

Abstract

Abstract A process for producing a non-woven web of thermoplastic polymer fibers comprises extruding a thermoplastic polymer through a series of die openings while passing a stream of hot gas from both sides of the die openings to impinge and attenuate the molten extruded resin fibers, wherein the gas is passed through a plurality of flow distribution holes and through a flow detector to intermix gas jets discharging from the holes.

Inventors

  • 👤 Peter G. Buehning

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-24 05:27
CPC Classifications
D; D01; D01D; D01D5/00; D01D5/08; D01D5/098; D01D5/0985; D04; D04H; D04H1/00; D04H1/40; D04H1/54; D04H1/56

Claims Analysis

Total Claims: 9
Claim 1
Independent Claim 206 words
A process for producing a non-woven web of thermoplastic polymer fibers comprising: (a) extruding thermoplastic polymer through a row of die openings in a triangular cross-sectional die head of a die body; (b) discharging gas along the entire length of the die onto each side of the molten resin as it is extruded to attenuate the molten resin as fibers in a plane away from said die openings, said gas having a substantially uniform velocity along the length of the die wherein said gas for each side is passed sequentially through a pipe discharging through a slit or plurality of holes into an air chamber designed to provide uniform velocity gas along the length of the air chamber, from the air chamber through a plurality of flow distribution holes in the die body, the gas discharging from the flow distribution holes into a longitunal groove in the die body as a plurality of streams said groove having gas deflector assembly to intermix the streams of gas discharging from the flow distribution holes and form said gas of substantially uniform velocity along the length of the die; and (c) collecting the attenuated fibers on a receiver in the path of said plain to form said nonwoven web.
Claim 2
Dependent Claim 206 words
A process for producing a non-woven web of thermoplastic polymer fibers comprising: (a) extruding thermoplastic polymer through a row of die openings in a triangular cross-sectional die head of a die body; (b) discharging gas along the entire length of the die onto each side of the molten resin as it is extruded to attenuate the molten resin as fibers in a plane away from said die openings, said gas having a substantially uniform velocity along the length of the die wherein said gas for each side is passed sequentially through a pipe discharging through a slit or plurality of holes into an air chamber designed to provide uniform velocity gas along the length of the air chamber, from the air chamber through a plurality of flow distribution holes in the die body, the gas discharging from the flow distribution holes into a longitunal groove in the die body as a plurality of streams said groove having gas deflector assembly to intermix the streams of gas discharging from the flow distribution holes and form said gas of substantially uniform velocity along the length of the die; and (c) collecting the attenuated fibers on a receiver in the path of said plain to form said nonwoven web.
Claim 3
Dependent Claim 27 words
The process of claim 1 wherein the gas is substantially isolated from said die body whereby said gas temperature and said molten resin temperature are independently controlled.
Claim 4
Dependent Claim 12 words
The process of claim 1 wherein said thermoplastic polymer is a polyolefin.
Claim 5
Dependent Claim 10 words
The process of claim 3 wherein said polyolefin is polypropylene.
Claim 6
Dependent Claim 18 words
The process of claim 4 wherein said polypropylene is emitted from said die head at about 500°-650° F.
Claim 7
Dependent Claim 18 words
The process of claim 5 wherein the gas is air emitted from the gas slots at 500°-650° F.
Claim 8
Dependent Claim 63 words
The process of claim 1 further comprising thermally isolating said stream of gas in said die body from the flow of thermoplastic polymer in said die body by providing dead air spaces along most of the path of said longitudinal groove, said dead air spaces being between said groove and most of the portion of said die body which contacts said thermoplastic polymer.
Claim 9
Dependent Claim 31 words
The process of claim 7 wherein the temperature of said polymer in said die body and the temperature of said gas in said longitudinal groove differ by at least 100° F.

References Cited (Backward Citations)

US3379811A Cited
US4078124A Cited
US3825379A Cited
US3825830A Cited
US3942723A Cited
US3981650A Cited
US4285655A Cited
US4295809A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1992-04-03 1992-10-03 1993-04-04 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1996-04-03 1996-10-03 1997-04-04 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2000-04-03 2000-10-03 2001-04-04 $7700.00 Window Closed / Lapsed

Assigned Categories & Tags

No categories assigned to this patent yet.

Assign Category Tag